The following code fragment at line 1213 tests for "port == NULL" but tries to print "port->port_num." if (port == NULL) { printk(KERN_ERR "gs_recv_packet: port=%d, NULL port pointer\n", port->port_num); return -EIO; }
Oops, a typo mistake here: the correct path to "serial.c" is drivers/usb/gadget/serial.c and not i2c.
Closing as obsolete (code has been rewritten)